The invention concerns a high power power supply with output power in excess of 5 kilowatts, by way of example, for the supply of electromagnets in the area of electromedicine and nuclear physics. In order to regulate the output current, power thyristors 28 are utilized within the two bridge rectifier circuits 2 and 3, operated with phase control regulation. In order to keep the output current constant, two transistor final control elements 10 and 11 regulated by a control-gain amplifier are used. Two charging capacitors 6 and 7 are provided for energy storage, the capacity of which is sufficiently large that the commutation of the power thyristors 28 transpires by means of self-extinguishing in a currentless state, whereby conducted as well as irradiated electrical interferences are eliminated.
This is a Request under the File Wrapper Continuing application procedure, 37 C.F.R. .sctn.1.62, for filing a continuation of the prior complete application Ser. No. 07/776,595, filed on Oct. 11, 1991, entitled HIGH-POWER POWER SUPPLY, now abandoned.
A transformer with a plurality of secondary windings with substantially similar coupling to the primary winding is used to facilitate synchronous rectification of the output by a rectifier attached to each secondary winding, reducing power losses compared to conventional power supplies with a single secondary winding coupled to a single rectifier. In a preferred embodiment, the transformer comprises at least two primary windings, with each primary winding coupled to at least two secondary windings.
A device and a method are disclosed for direct current voltage power supply to a traction system by means of converters from different alternating current or direct current voltages available on a power supply line. The power supply device is supplied with power by means of a first power supply element and a second power supply element connected to the power supply line. In this supply device the first power supply element is connected to the primary winding of the power supply transformer by a first connection element. The second power supply element is connected either to the power supply terminal of the traction system or to the mid-point of the series converters by a second connection element.
An isolation device feasible for protecting a parallelable power supply from a reverse current comprises a field-effect transistor (FET) coupled in series between a voltage output terminal of the parallelable power supply and a load, and a transistor control circuit including a voltage comparator for detecting if a reverse current is flowing through the FET, a duty comparator circuit for detecting if an infinitesimal reverse current which is undetectable by the voltage comparator circuit is flowing through the FET, a transistor driving circuit for performing a logic AND operation with an output state of the voltage comparator circuit and an output state of the duty comparator circuit to drive the FET to turn on or off in response to the result of the logic AND operation, and an auxiliary circuit for driving the FET to turn off when the parallelable power supply is short-circuited.
A power converter for converting three phase input power to DC output power and a method of effecting such conversion. The power converter includes: (1) three single phase DC converters, each having outputs, that receive the three phase input power, (2) a DC/DC converter coupled to the outputs of the three single phase DC converters and (3) a converter selection circuit, associated with the three single phase DC converters, that selects a selected subset of the three single phase DC converters as a function of an electrical characteristic of each phase of the three phase input power to conduct a portion of the three phase input power to the DC/DC converter, the converter selection circuit permitting the power converter to operate on the three phase power with less than three DC/DC converters.
The AC-DC converter comprises a first rectifier circuit having a three-phase input and an output in DC. A compensating device is connected between the input and output of the first rectifier circuit to compensate the stray disturbances generated by a current flowing in said first rectifier circuit. The compensating device makes a compensation current flow between the three-phase input and the DC output. Said compensating circuit comprises a second rectifier circuit with controlled rectifiers connected to the three-phase input, a step-up circuit connected between the second rectifier circuit and the DC output, and a control circuit to control the step-up circuit and the second rectifier circuit.
